【单选题】After supper,my mother often washes in the kitchen.
【单选题】Her mother ______ her clothes every Sunday. [ ]
【单选题】What does Linda do before dinner?
A.
She washes the dishes.
B.
She helps her mother with the cooking.
C.
She helps her mother with the cooking and washes the dishes.
【单选题】风力角α随风舷角θ增大而增大,θ=40°~140°之间,α大约在多少度之间?
【单选题】下列关于氯气的描述正确的是( )。
D.
氢气在氯气中燃烧,发出苍白色火焰,瓶口出现白雾
【多选题】下列关于空气的描述中正确的有?
F.
氢气、氦气等稀有气体的含量是空气中微生物生存的决定条件
【单选题】研究发现,苍蝇之所以免受细菌感染,是由于体内产生过氧化氢(H 2 O 2 )下列关于过氧化氢的描述正确的是 [ ]
【单选题】风舷角在80°~100°之间的风称为()。
【单选题】风舷角在80°~100°之间的风称为:()